Mounting for electrical switches



1952 1.. CRUMP ET AL MOUNTING FOR ELECTRICAL swncmzs Filed March 15, 1948 7 //.O H Z 7 v u a i w w H 0 M8 M f A ,5 w 7/ KL M H 5 l 4 i u u. IF 5 a E F a hunk. 2 nun! 2 Z a lint It; V mu nfi w fi fi 1 7 9y 0 3/ my 4% 02w 5% 51/4 5 g 0 f d INVENTOR Lend u L Jo hn T. F!

(mu m P ATTORNEY Patented Oct. 14, 1952 MOUNTING FOR ELECTRICAL SWITCHES Lindell Lloyd Crump, Kirkwood, and John T. Finley, St. Louis, Mo.

Application March 15, 1948, Serial No. 14,958

3 Claims. 1

This invention relates generally to electrical switches of the type adapted to be mounted on suitable supporting structures and intended for use in interrupting the flow of electrical current through circuits in which the switches are interposed on occurrence of electrical faults in said circuits, the predominant object of the invention being to provide an improved mounting for such electrical switch which is provided with a base member from which insulators extend, and which includes improved and simplified means for securing said insulators to said'base member.

Fig. l is a side elevational view of an electrical switch provided with a mounting constructed in accordance with the present invention.

Fig. 2 is an enlarged cross-section takenon line 2-2 of Fig. l. V

Fig. 3 is a fragmentary, vertical sectional view taken on line 3-3 of Fig. 2.

In the drawing, wherein is shown for purposes of illustration, merely, one embodiment of the invention, A designates theillustrated switch structure generally. The switch A includes a base member 1 which preferably, though not necessarily, is channel-shape in cross-section, said base member I having associated therewith suitable clamping means 2 for securing it to a supporting structure S, such, for instance, as a" crossarm of a pole, whereby the switch is mounted in position for use.

. The switch A is provided with a pair of insulators 3 and 4 which are supported by and extend outwardly from the base member I. The base member I of the particular switch illustrated in the drawing is disposed vertically with the insulators 3 and 4 being extended horizontally therefrom in vertical spaced relation. However, such arrangement is not essential to the in vention as the parts mentioned may be disposed in various other positions as described.

The particular switch illustrated in the drawing includes a supporting bracket 5 which is clamped to the outer portion of the upper insulator 3, said bracket having secured thereto, by means of suitable fastening means 6, an upper terminal I. Secured to the upper terminal I through the instrumentality of fastening means 8' is an upper contact arm 8, and secured to the upper terminal I by means of a connector 9 is an incoming electrical conductor 10.

' In like manner, the illustrated switch includes a supporting bracket II that is clamped tothe outer portion of the lower insulator 4, said bracket I I having secured thereto, by means of suitable attaching means I2, a lower terminal 13. Associated with the lower terminal l3, and secured thereto through the instrumentality of suitable fastening means I4, is a lower contact arm IS. The lower contact arm I5 is formed of inherently resilient material and in order to impart additional resiliency to it said lower contact arm is provided withv a pair of coiled portions 16, only one of which is shown in the drawing. The lower terminal 13 has secured thereto, by means of a suitable connector ii, an outgoing electrical conductor 18.

The upper contact arm 8 and the lower contact arm l5 are'provided with gripping portions that are produced by rearwardly extended, forward portions [9 of said contact arms, these gripping portions serving to grip portions of oppos'edcables which form parts of a fuse link 20. The fuse link 20 includes a tubular element 2|, formed of suitable electrical insulating material, which embraces a fusible section of the fuse link (not shown), and, also, eye elements 22 are provided at the outer ends of the cables 20' of the fuse link which serve an obvious function in the application of the fuse link to the contact arms'B and I5 with the aid of a suitable insulated tool.

When the fuse link is in its assembled relation with respect to the contact arms 8 and 15 it is placed under tension by the tendency of the outer portion of the lower contact arm to swing downwardly in response to force stored up in the coiled portions l6 thereof, the intact fuse link preventing such movement of said lower contact arm. However, when a fault occurs in the circuit in which the switch is interposed, the fusible section of the fuse link is fused, whereby the cables 20 of the ruptured fuse link are pulled apart by the released downwardly swinging lower contact arm so as to interrupt any are which may be produced within the tube 2| of the fuse link.

The switch structure described immediately above is disclosed and claimed in United States Patent No. 2,086,028, granted July 6, 1937.

As heretofore stated, the gist of this invention is the manner of securing the insulators 3 and i to the base member I of thecutout A. The fastening means comprise a pair of tubular elements 23 and 24, the tubular element 23 being related to the upper insulator 3, while the tubular element 24 is related to the lower insulator 4. The base member I has formed therethrough a pair of openings 25 and 26, and the rearward end portions of said tubular elements 23 and 24 are extended through said openings (see Fig. 3). Also, the tubular elements are welded to the inner face of the apertured wall of the base member by means of welds 21 and 28 so as to very securely fix said tubular elements to said base member in positions where said tubular elements project forwardly from said base member. The insulators 3 and 4 are provided with longitudinal bores, and the forward portions of the tubular elements 23 and 24 are disposed in the rear portions of said bores of said insulators. Washers 29 and 30 are arranged in embracing relation with the tubular elements 23 and 24 and are interposed between the rear faces of the insulators and adjacent face portions of the base member I, said washers being formed of suitable resilient material, cork, for instance, which provide pads that serve to protect the rear portions of the insulators from injury caused by contact of said rear portions of the insulators with the base member.

As is shown to good advantage in Fig. 2, the

.diameters ofthe'tubular elements 23 and 24 are substantially. less than the diameters of the bores of the insulators-3 and 4, and interposed between a portion of each of the insulators 3 and 4 and an adjacent portion of the related tubular element is a washer 3| of substantially V-shaped formation. Each of the V'-shaped washers 3| has a bolt opening 32 formed centrally thereithrough and the bolt opening of each V-shaped Washer is alined with similar bolt openings 33 and 34 that are formed, respectively, through wall portions of the related insulator and tubular element. Additionally; each insulator has associated therewith a saddle member 35 which is shaped in cross-section as is shown to good ad- :Vantage in Fig; 2, said saddle member also having aboltopening 36 formed therethrough which is alined with the bolt openings formed through wall portions of the related insulator and tubular element. Thefastening means at the inner end of each of the insulators 3 and 4 includes a bolt '37 whose shank extends through the bolt openings of the related saddle member, insulator, V-shaped washer, and. tubular element. The head of each bolt contacts with the related saddle member and the screwthreaded shank of each of said bolts has mounted thereon a nut 38 which contacts with the inner face of the related tubular element.

By referring to Fig. 2 it will be noted that when the fastening means are in their assembled condition, the opposed outer ends of the washers make line contact with face portions of the bores of theinsulators 3 and 4, and that spaces are present between other portions of the washers and adjasc'entfaee portions of the bores of the insulators. Due to the fact that the washers 3| are formed of spring material, these spaces cause the washers to serve as resilient, compensating means which permits the insulators and the metallic parts secured thereto to expand and contract in response to atmospheric temperature changes without loosening of the fastening means, and prevents such excessive tightening of the bolts as would ;,crack or fracture the insulator material.

yAttention is directed to United States Patent No. 2,140,904, granted December 20, 1938, wherein aconnecting device is disclosed and claimed which includes a V-shaped washer similar to the vV-shaped washers forming parts of the present invention. Y

-By--employing the fastening means disclosed .herein for securing the insulators 3 and 4 to the base member [of the switch A, much lighter and less expensive insulators may be used as parts of the cutout. Also, the use of the improved fastening means of the present invention eliminates the need for certain metallic caps with which insulators were heretofore provided and which served as means for facilitating bolting of the insulators to the base members.

We claim:

1. A support for an electrical switch comprising a base member, an insulator supported by said base member and extended outwardly therefrom, said insulator being provided with a bore formed longitudinally therein which is open at an end of the insulator, and said insulator being adapted to support part of a switch, and means for attaching said insulator to said base member, the lastmentioned means comprising a tubular element having an end portion that is extended through an opening formed in a wall of said base member and which is welded to said wall of said base member, said tubular element being projected outwardly from said base member and being extended into the bore of said insulator, and means including a yieldable V-shaped washer which is interposed between a face portion of the bore of said insulator and a portion of said tubular element for securing said insulator to said tubular element.

2. A support for an electrical switch comprising a base member, an insulator supported by said base member and extended outwardly therefrom, said insulator being provided with a bore formed longitudinally therein which is open at an end of the insulator, and said insulator being adapted to support part of a switch, and means for attaching said insulator to said base memher, the last-mentioned means comprising'a tubular element which is fixed to and projects outwardly from said base member and which extends into the bore of said insulator, and means for securing said insulator to said tubular element, the means for securing said insulator to said tubular element comprising a saddle member that contacts with the outer surface of said insulator and which is provided with a bolt opening formed therethrough that is alined with bolt openings formed through wall portions of said insulator and said tubular element, a bolt and nut assembly whose bolt shank extends through said bolt openings of said saddle member, said insulator, and said tubular element, and a substantially V-shaped washer formed of resilient material that is associated with said bolt inwardly of said insulator in interposed relation between the wall of said insulator and the wall of said tubular element and which provides for yieldable attachment of said insulator and said tubular element.

3. A support for an electrical switch comprising a base member, an insulator supported by said base member and extended outwardly therefrom, said insulator being provided with a bore formed longitudinally therein which is open at an end of the insulator, and said insulator being adapted to support part of a switch, andmeans for attaching said insulator to said base member, the last-mentioned means comprising a tubular element which is fixed to and projects outwardly from said base member and which extends into the bore of said insulator, and means for securing said insulator to said tubular element, the means for securing said insulator to said tubular element comprising a saddle member that contacts with the outer surface of said insulator and which is provided with a bolt opening formed therethrough that is alined'with bolt 5 openings formed through wall portions of said REFERENCES CITED insulator and said tubular element, a bolt and The following references are of record in the nut assembly whose bolt shank extends through fi said bolt openings of said saddle member, said 18 of this patent" insulator, and said tubular element, and a sub- 5 UNITED STATES PATENTS stantially V-shaped washer formed of resilient 'Number Name Date material that is associated with said bolt in- 894,6l6 Fay July 28, 1908 wardly of said insulator in interposed relation 1,725,122 Aalborg Aug. 20, 1929 between the wall of said insulator and the wall of 2,140,904 Fox Dec. 20, 1938 said tubular element and which provides for 10 yieldable attachment of said insulator and said FOREIGN PATENTS tubular element, the nut and bolt head of said Number Country Date bolt and nut assembly contacting with the inner 4241637 England 221 1935 face of said tubular element and with said saddle 270,521 Germany 1914 member. 15

LINDELL LLOYD CRUMP. JOHN T. FINLEY. 

